(1) Field of the Invention
This invention relates to substrate treating apparatus for carrying out a predetermined treatment, such as cleaning or resist coating, of spinning substrate.
(2) Description of the Related Art
A conventional substrate treating apparatus of this type, generally, includes a rotary shaft extending vertically and drivably connected to a motor, and a substrate support mechanism mounted on an upper end the rotary shaft. A known substrate support mechanism has a spin base defining vacuum suction bores for suction-supporting a lower surface (usually a reverse surface) of a substrate. Another known substrate support mechanism has a spin base with three or more substrate supporting pins arranged peripherally thereof for supporting a substrate in three or more peripheral positions of the substrate.
In the conventional apparatus, the torque of the motor is transmitted to the rotary shaft, with a substrate placed on the substrate support mechanism. Thus, the substrate is spun about the axis of the rotary shaft, together with the rotary shaft and substrate support mechanism. In this state, the substrate receives a predetermined treatment such as cleaning or resist coating.
The conventional apparatus has the following drawbacks.
In the conventional apparatus, the motor and rotary shaft are arranged below the substrate and occupy a large space in the vertical direction. Further, the motor and other components below the substrate are obstructive to treatment of the lower surface of the substrate. That is, although the conventional apparatus is capable of treating one surface of the substrate, it is difficult or impossible to treat the opposite surfaces of the substrate.